Without metrics of some kind from Wube I guess we aren't likely to know for sure, but I doubt very much it is common to run old versions of the game on Steam. I

Without metrics of some kind from Wube I guess we aren't likely to know for sure, but I doubt very much it is common to run old versions of the game on Steam. I bet you that most people are simply running on the latest version at all times. That solves the MP issue, and plenty of mods don't need to be updated for each game version.